Collapsible punch



2, 1946. -J. J. THAYER 2,400,961

COLLAPS IBLE PUNCH Filed Jan. 7, 1943 4 Sheets-Sheet l 5 J. J. THAYERCOLLAPSIBLE PUNCH V Filed Jan. 7, 1943 4 Sheets-Sheet 2 May 28, 1946.

COLLAPS IBLE PUN C H 4 Sheets-Sheet 3 Filed Jan. 7, 1943 Patented May28, 1946 COLLAPSIBLE PUNCH Josephus J. Thayer,

to General Foods Battle Creek, Mich., assignor Corporation, New York, N.Y.,

a corporation of Delaware Application January 7, 1943, Serial No.471,609

12 Claims.

This invention relates to punches for forming articles from suitableblank material, such as metal, cardboard, etc, and more particularly .topunches which can be collapsed to release the formed articles.

One of the problems in making such articles by a punch and die operationis to free the completed article from the punch, particularly when it isformed with interior threads or other projections. For purposes ofillustration, the invention will accordingly be described hereinafterwith reference to the forming of interiorly threaded caps for bottles orjars, etc, but it wiil be understood that the invention is useful inconnection with the formation of any article which is not freelyreleased by the punch. Collapsible punches have been proposed heretoforefor such operations, but it is difficult to provide a simple andpractical punch structure which is readily and quickly collapsible asrequired in commercial production and yet at the same time is capable ofwithstanding the substantial compressive stresses to which it issubjected in the formation of the caps. Hence in actual practicethreaded caps are usually removed from the punch by mechanical deviceswhich engage each cap and rotate it to spin it off the punch.

The principal objects of the present invention are to provide a novelcollapsible punch which is of simple but durable construction, which canbe readily and practically instantaneously collapsed to free the cap,and which atthe same time is strong and rigid when expanded to Withstandthe substantial compressive stresses necessary to form the cap.

Other objects will appear more fully hereinafter as the description ofthe invention proceeds.

One embodiment of the invention has been illustrated in the accompanyingdrawings, but it is to be expressly understood that said drawings arefor purposes of illustration only and are not to be taken as adefinition of the limits of the invention, reference being had to theappended claims for this purpose.

In the drawings:

Fig. 1 is an elevation of a punch embodying the invention, together withassociated operating mechanism;

Fig. 2 is a section on the line 2-2 of Fi 1;

Fig. 3 is a section on the line 3-3 of Fig. 1;

Fig. 4 is a section on the line 4-4 of Fig. 1;

Fig. 5 isa section on the line 5--5 of Fig. 1;

Fig. 6 is an enlarged sectional view corresponding to the lower part ofFig. 2, but with the punch head collapsed;

Fig. 7 is a section on the line 'i-l of Fig. 6;

Fig. 8 is an enlarged view of the punch head, with a formed cap thereon;

Fig. 9 is a detail view of the cap itself Figs. 10 and 11 show thearrangement of the elements forming the punch head, Fig. 10 being asection on the line Ill-H] of Fig. 1 and Fig. 11 being a bottom plan;and

Figs. 12 and 13 arediagrammatic views illustrating the collapse of thepunch head.

A suitable punch head adapted to form an interiorly threaded cap ofcardboard or like fibrous material is shown in Figsli and 2 and enlargedin Fig. 8. The cap material may suitably comprise an outer layer 1 offairly stiff cardboard and an inner layer 2 of relatively spong materialadapted to be compressed into a thread by virtue or the spiral groove 3of the punch head. .The cap blankt is positioned over the die opening 5(Fig. 1) and the punch is moved into and out of the die in any suitablemanner, as by mounting it on'the vertically movable cross head of apunch press, part of which is shown at 6 in Figs. 1 and 2. The blank isdrawn into cap-shape and the interior thread formed on downward movementof the punch, and if a continuous web or strip of blank material isused,'it is pinched ofi between the shoulder 1 of the punch and the edgeof the die opening. The punch is then withdrawn from the die, carryingwith it the formed cap, and is collapsed as hereinafter described torelease the cap. It will be understood, however, that the i use of theinvention is not restricted to forming caps of this particular type ormaterial or to this particular method of operation.

The preferred arrangement of the several elements forming thecollapsible punch head are shown in detail in Figs. 8, 10 and 11. Theseelements are four in number, comprising two pairs of elements 8 and 9respectively, the elements of each pair being alike but diametricallyopposite. Th outer surfaces of these elements are curved on a commonradius so that, when expanded as shown in Figs. 10 and 11, they form asubstantially continuous circular periphery for the punch head; Theelements 8 are in effect wedge-shaped, the sides I!) of each of theseelements extending inwardly from the ends of its curved periphery anddiverging from one another. The elements 9 are provided withcorrespondingly inclined surfaces I I, and preferably the surfaces II]and I l are in tight engagement when the punch head is expanded.

As hereinafter described, the elements of each pair are movable inwardlytoward each other along their common diameter. Owing to the inclinationof the surfaces [9 and H, inward movement of the elements 8 to theposition shown in Fig. 12 results in separation of these surfaces sothat the elements 9 may then move inwardly to the position shown in Fig.13. During this movement the tips 52 of the elements 9 move along chordsof the expanded punch head circle and thus are withdrawn within itscircumference. It will be understood that Figs. 12 and 13 arediagrammatic views illustrating the collapsing operation and that it isnot necessary for the elements 8 to be moved completely inwardly beforethe elements 9 are moved inwardly, as the movement of the latter maystart immediately after initial displacement of the former and bothcollapsing movements thereafter continue simultaneously.

In order to provide for the collapsing move-' ment described above, thepunch head elements 8 and 9 are each carried by supporting members whichare pivoted on the body of the punch, the rocking movement of thesesupports about their pivots causing the inward and outward movement ofthe punch head elements. To accommodate these pivoted supporting memberswhile at the same time housing them within the circular exterior of thepunch, the body of the punch is preferably provided with longitudinallyextending radial slots in which the supports operate. This constructionis preferably obtained (Fig. by forming the body of the punch of foursimilar parts l3 each forming one quadrant of the punch body, said partsbeing spaced from one another to provide four longitudinally extendingdiametrically opposite slots intersecting to provide a central openingthrough the punch body. The body parts l3 may have any suitable externalshape and may be assembled and mounted in any suitable manner. In theform shown, each body part is square in cross section except at itslower portion 14 which is rounded to form a circular punch body capableof entering the die opening '5. The body parts I 3 are suitably mountedon the cross head 6 by means of a supporting plate I5 secured to thecross head by bolts IS, the body parts being secured to this plate bystuds H. To aid in centering and aligning the punch body, the upper endof each body part [3 is provided with one quadrant of a raised annularrib l8 engaging an annular groove IS in the lower face of the supportingplate l5.

The pairs of punch head elements 8 and 9 are carried by correspondingpairs of pivoted supporting members and 2!, each of which is pivoted inany suitable manner in one of the longitudinal slots in the punch body.As herein shown, the supports 29 are carried by pivot pins 22 and thesupports 2| by pivot pins 23, these pivot pins being disposed atdiiferent elevations as shown in Figs. 6 and '7 and each extendingthrough two of the punch body parts l3.

The supports 29 and 2! are thus free to rock about their pivots so as tomove the punch head elements 8 and 9 inwardly from expanded position.Preferably this movement is effected and controlled by means of anoperating member 24 slidable longitudinally in the central opening inthe punch body and adapted to engage and spread the inner ends of thesupports. Referring particularly to Figs. 6 and '1', these supportsterminate in rounded heads 25 and 26, which may if desired extend intoor through slots in the supporting plate (5 which are aligned with theslots in the punch body. The heads 25 and 5 are engaged respectively bycam surfaces 21 and 28, when the operating member 24 is retracted orwithdrawn into the punch body, so as to spread or separate the innerends of the supports and thus move the punch head elements 8 and 9inwardly as described above with reference to Figs. 12 and 13. It willbe understood that the cam surfaces are arranged so that the inwardmovement of the punch head elements 8 begins slightly ahead of theinward movement of the punch head elements 9, but so that the collapseof the punch head takes place substantially instantaneously.

When the operating member 24 is moved in the opposite direction, itsouter end engages inclined cam surfaces 29 of the punch head elements 8and similar inclined cam surfaces 39 of the punch head elements 9 tomove these elements outwardly to expanded position, the cam surfaces 2!and 28 being simultaneously withdrawn from engagement with the heads 25and 28 of the rocking supports. Further outward movement of theoperating member projects its outer end between the punch head elementsas shown in Figs. 10 and 11, the dimensions of the operating member andof the cam projections 29 and 38 preferably being such that the expandedpunch head is solid along diameters at right angles. The outwardmovement of the punch head elements may be limited by the engagement ofthe heads 25 and 26 of the supports with the surfaces of the operatingmember 24.

It will be seen that the operating member 24 has a substantiallyrectangular cross section, but that its thickness in either directionvaries at different points along its length. Accordingly the bar has abasic cross sectional shape and area corresponding to the central holethrough the punch body which is defined by the inner rectangular cornersof the body parts i3, with the raised cam surfaces, etc., of varyingheight projecting into the slots between these parts as shown in Fig. 5.Preferably the raised surfaces extend the full width of the slots andthus guide the longitudinal movement of the operating member, the latterhaving in effect rectangular guide grooves along each corner which slideon the inner rectangular corners of the body parts 13.

Any suitable means may be employed for operating the member 24 in timedrelation with the operation of the cross head 6, but preferably it isretracted pneumatically to release the formed cap, in which case it mayconveniently be returned to expand the punch head by resilient meanscompressed during its'movement of retraction. To these ends, theoperating member 24 is made round in cross section to pass slidablythrough a bushing 3| and into a pneumatic cyl inder 32. This cylinder32, as shown, is housed in a recess in the cross head and mounted on thesupporting plate I5 by means of bolts 33, spacers 34 separating thecylinder from the plate and providing space for the heads of the boltsll. Within the cylinder 32, the operating rod 24 carries a piston 35which is secured by washers 3t and 3'? between a shoulder 38 on theoperating rod and a nut 39 on its end. Air under pressure is admitted tothe cylinder beneath the piston by a passage 49, and the upward strokeof the piston is limited in any suitable manner as by means of anannular retaining member 4| secured to the cylinder 32 by means ofscrews 42. Upward movement of the operating rod 2Q serves to compress areturn spring 43 housed in a sleeve 44 secured to the cross head 6 bymeans of'screws 45, the

upper end of the spring bearing against an ad, justing screw 46 threadedin a plate 4'! which is secured to the sleeve 44 by the bolts 45. Thereturn stroke ofthe operating member is limited by engagement of thewasher 36 with the bushing 3 l.

The operation of the apparatus will be understood from the foregoingdescription, and can be summarized as follows. With the punch head inexpanded position and the parts as shown in Fig. 1, the cross head 6descends and the punch enters the die opening and forms the threaded capshown in Fig. 9. The cross head then ascends, raising the punch out ofthe die opening and carrying with it the formed cap. After the end ofthe punch has cleared the die, air under pressure is admitted tothe'cylinder 32, retracting the operating rod 24 and collapsingthe'punch head to release the cap. This operation takes place veryrapidly, and at the same time the spring 43 is compressed so that assoon as the air pressure is cut oil, the operating rod 24 is snappedback to its outermost position, expanding the punch head for the nextforming stroke. The construction is very simple and comprises few parts,but

its operation is practically instantaneous and at the same time a strongrigid punch head is provided which is capable of withstanding thesubstantial pressures to which it is subjected in the forming operation.

While only one embodiment of the invention has been described andillustrated in the drawings, it is to be expressly understood that thisembodiment is for purposes of illustration only, and that variouschanges can be made in the form, details of construction and arrangementof athe parts without departing from the spirit of the invention, manyof which changes will now occur to those skilled in the art. Accordinglyreference is to be had to the appended claims for a definition of thelimits of the invention.

What is claimed is: l l

1. A collapsible punch comprising a plurality of elements forming apunch head of the desired shape when in expanded position, supports forsaid elements each extending longitudinally of and pivoted intermediateits ends on the punch, whereby said elements are movable inwardly andoutwardly between expanded and collapsed positions, a member extendingcentrally through said punch and movable longitudinally therein, said.

member on movement in one direction rocking said supports about theirpivots to move said elements to. expanded position and on movement inthe other direction rocking said supports about their pivots to movesaid elements to collapsed position, pneumatic means for moving saidmembar in said second direction, and resilient means stressed bymovement of said member in said second direction for returning saidmember in said first direction.

2. A collapsible punch comprising two pairs of oppositely disposedelements forming a punch head of the desired shape when in expandedposition, said elements being carried by corresponding pairs of supportseach extending longitudinally of the punch and pivoted intermediate itsends thereto, an actuating member substantially rectangular incrosssection extending centrally through said punch and longitudinallymovable therein, each surface of said member being shaped to engage oneof said supports inwardly of its pivot on retraction of said member tomove said elements to collapsed position, and said member engaging saidsupports outwardly of their pivots on movement in the opposite directionto move said elements to expanded position, pneumatic means forretracting said member, and resilient means stressed by retraction ofsaid member for moving it in said opposite direction.

3. A collapsible punch comprising two pairs of oppositely disposedelements forming a. punch head of the desired shape when in expandedposition, said elements being carried by correspondnally of the punchand pivoted intermediate its ends thereto, an actuating membersubstantially rectangular in cross section extending centrally 3 throughsaid punoh'and movable longitudinally I gage said supports inwardlytherein, said member in its outermost position separatingand maintainingsaid elements in expanded position with the inner ends of said supportsengaging said member, said member also raised surfaces adapted onretraction to engage said inner ends and move said elements to collapsethe punch head, pneumatic means for retracting said member, andresilient means stressed by retraction of said member for moving it inthe opposite direction.

4. A collapsible punch head comprising two pairs of oppositely disposedelements forming a punch head of the desired shape when in exposition, apunch body comprising four quadrantal parts spaced from one another toprovide longitudinal slots in the sides of the punch with theintersection thereof forming a central opening, said elements beingcarried by corresponding pairs of supports each pivoted intermediate itsends in one of said slots, an actuating member movable longitudinally insaid opening, the surfaces of said member being shaped to enof theirpivot on retraction of said member and to move said elements andcollapse the punch head, and said member engaging said supportsoutwardly of their pivots on movement in the opposite direction to movesaid elements and expand the punch head, pneumatic means for moving saidmember in said one. direction, and resilient means stressed by movementof said member in said one direction for moving it in said oppositedirection.

5. A collapsible punch comprising a punch body; two pairs of supportspivoted on said body the ends of which carry elements forming inexpanded position a substantially circular punch head, each element ofone pair of diametrically opposite elements having outwardly taperingsurfaces adapted to cooperate with adjacent outwardly tapering surfacesof the elements of the other pair to form a substantially continuousperiphery, a central actuating member the end of which is adapted to beadvanced between said pairs of elements when expanded, the diametricaldimensions of said member along the two diameters corresponding to saidpairs of elements being such that the expanded punch head is solidlyheld punch head is expanded and to retract said memher and collapse thepunch head.

6. A collapsible. punch comprising a punch body, two pairs of supportspivoted on said body. the ends of which carry elements forming inexpanded position a substantially circular punch head, each element ofone pair of diametrically opposite elements having outwardly taperingsurfaces adapted to cooperate with adjacent outwardly tapering surfacesof the elements of the other pair to form a substantially continuousperiphery, a central actuating member the end of which is adapted tov beadvanced between said pairs of eleidly held along ments when expanded,the diametrical dimensions of said member -along the two diameterscorresponding to said pairs of elements being such that the expandedpunch head is solidly held along both said diameters, means foradvancing said member with said end camming said elements to expandedposition as it advances between them, and means for moving said memberin the opposite direction and collapsing said punch head.

7. A collapsible punch comprising a punch body, two pairs of supportspivoted on said body the ends of which carry element forming in expandedposition a substantially circular punch head, each element of one pairof diametrically opposite elements havingoutwardly tapering surfacesadapted to cooperate with adjacent outwardly tapering surfaces of theelements of the other pair to form a substantially continuous periphery,a central actuating member the end of which is adapted to be advancedbetween said pairs of elements when expanded, the diametrical dimensionsof said member along the two diameters corresponding to said pairs ofelements being such that the expanded punch head is solidly held alongboth said diameters, means for expanding said elements and advancing theend of said member between them, means for moving said member in theopposite direction to engage and spread said sup-ports above theirpivots, thereby collapsing the punch head.

8. A collapsible punch comprising a punch body, two pairs of supportspivoted on said body the ends of which carry elements forming inexpanded position a substantially circular punch head, each element ofone pair of diametrically opposite elements having outwardly taperingsurfaces adapted to cooperate with adjacent outwardly tapering surfacesof the elements of the other pair to form a substantially continuousperiphery, a central actuating member the end of which is adapted to beadvanced between said pairs of elements when'expanded, thediametricaldimensions of said member along the two diameterscorresponding to said pairs of elements being such that the expandedpunch head is solboth said diameters, means for expanding said elementsand advancing the end of said member between themfmeans for; moving saidmember in the opposite direction to engage and spread said supportsabove their pivots to collapse said punch head, said member initiatinginward movement of saidone pair of elements before that of said otherpair of elements.

9. A collapsible punch comprising a punch body, two pairs of supportspivoted on said body the ends of which carry elements forming inexpanded position a substantially circular punch head, each element ofonepair of diametrically opposite elements having outwardly taperingsurfaces adapted to cooperate with adjacent outwardly tapering surfacesof the elements of the other pair to form a substantially continuousperiphery, a central actuating member the end of which is adapted to beadvanced between said pairs of elements when expanded, the diametricaldimensions of said member along the two diameters corresponding to saidpairs of elements being such that the expanded punch head is solidlyheld along both said diameters, means for expanding said elements andadvancing the end of said member between them, means for moving saidmember in the opposite direction to eneach of which carries a gage andspread said supports above their pivots to collapse said punch head,said member initiating inward movement of said one pair of elementsbefore that of said other pair of elements, and the inward movement ofsaid one pair of elements being morelrapid than that of said other pairof elements.

10. A collapsible punch comprising a punch body, two pairs of leverspivoted on said body each of-which carries a punch head element at itsouter end, said elements forming in expanded position a substantiallycircular punch head, each element of one pair of diametrically oppositeelement having outwardly tapering surfaces adapted to cooperate withadjacent outwardly tapering surfaces of the elements of the other pairto form'a substantially continuous periphery, a central actuating membermovable longitudinally relative to the punch, means for expanding thepunch head on outward movement of said memher, and cam rn'eans'on saidmember adapted on inward movement thereof to engage said levers abovesaid pivots'and collapse the punch head, the cams and lever arms beingproportioned to cause more rapid inward movement of said one pair ofelements than of said other pair of elements.

11. A collapsible punch. comprising a punch body, two pairs of leverspivoted on said body each of which carries a punch head element at itsouter end, said elements forming in expanded position a substantiallycircular punch head, each element of one pair of diametrically oppositeelements having outwardly tapering surfaces adapted to cooperate withadjacent outwardly tapering surfaces of the elements of the other pairto form a substantially continuous periphery, a central actuating membermovable longitudinally relative to the punch, means for expanding thepunch head on outward movement of said member and said member beingadapted on inward movement to engage said levers in a plane above theirpivots and spread them substantially equal amounts to collapse the punchhead, the

' pivots of the levers carrying said one pair of elements being at agreater distance from the punch head than the pivots of said other pairof punch elements.

12. A collapsible punch comprising a punch body, two pairs ofleverspivoted on said body punch head element at its outer end, said elementsforming in expanded position a substantially circular punch head, eachelement of one pair of diametrically opposite element having outwardlytapering surfaces adapted to cooperate with adjacent outwardly taperingsurfaces of the elements of the other pair to form a substantiallycontinuous periphery, a central actuating member movable longitudinallyrelative to the punch, cam means on said member adapted on inwardmovement thereof to engage said levers above said pivots and collapsethe punch head, the cams and lever arms being proportioned to cause morerapid inward movement of said: one pair of elements than of said otherpair of elements, and cam means adapted to expand said punch head onoutward movement of said member and arranged to cause more rapid outwardmovement of said one pair of elements than of said other pair ofelements.

JOSEPHUS J. THAYER.

